Went to a friends house the other day and saw a big roll of copper wire on the floor. He said he was going to turn it on for the copper. Said I could have if I want it but its 30ga didnt know if that could be used or not.
30 ga can be used if you want to try it, but i doubt it will sound like a regular pickup. 30 ga wire will mean that fewer turns will be placed onto the coil, which leads to a lower inductance. It will also have a lower resistance value because the resistance per foot of 30 ga wire is much less than the resistance per foot of 42 awg.

You may want to try to make a pickup out of it just to see how it sounds. Lower inductance pickups generally are much more clean sounding than a higher inductance pickup from what I understand. I'm not sure how exactly the lower resistance will affect the output volume of the pickup. It should also have a better overall frequency response as it will have a lower impedance at all frequencies than a pickup with a higher inductance.
Well it would be free wire and I have a set of epi pickups that I could use for parts. So nothing would be lost in the effort. I saw on the net a spool of the same size was 180 bucks.
i'd say do it. You may find an awesome tone. Experiment with the magnets too. Rock Monkey Guitars sells them.
Im gonna imagine there will be a limit to the amount of wraps Ill be able to get away with do to the ga of wire. Im not big on high output pickups anyways. But I do like clarity. And it will give me a chance to mess with building some simple onboard boosters or EQs. We will see where this goes. Nothing better than free parts for experimentation. After taking the epi pickups apart see they do a pretty crappy wax potting job.
30 is pretty big for pups. You'd have to have a custom bobbin to accomodate the bigger wire and the higher number of turns you'll need. This'll really mess with the inductance. I say do it. It could be very awesome!